pimpleDyMFoam -- lowered viscosity -- time step continuity errors getting large
 

I'm working on some cases with pimpleDyMFoam, which I have gotten to mesh and solve fairly well, but then when I go to drop nu from 1e-6 to 6.7e-7, I am getting time step continuity errors that go up into the 6000 range after a few seconds. This then sets my deltaT so low that the solution effectively halts. Any ideas why this would happen?

My guess would be something happening with either:
or with the turbulent quantities. So either fvSolution or fvSchemes file. Perhaps changing to a lower order scheme, different equation solver, adding underrelaxation or pushing down your tolerances would prevent it from blowing up. It would all depend on how the process actually takes place - showing your log file would help a bit in determining what is actually going on.

Are you using the same mesh for both viscosities? What kind of moving mesh are you using?

All the best,

A